Esophageal carcinoma is endemic in the Ho Nam Province in China. Characterization of antigens unique to these tumors would be useful for diagnosis of this carcinoma. Glycolipids isolated from esophageal tissues obtained from 11 cancer patients, 10 normal individual controls, and a cultured esophageal carcinoma line were examined using several monoclonal antibodies. Several glycolipids differ in amount between the tumor samples and normal controls. Both neutral and sialylated glycolipids containing 3-fucosyllactosamine sequences differ in expression between the tumor and control tissues and a heptaglycosylceramide reacting with antibodies to this sequence is found only in the tumor tissues. The same glycolipids are detected in the cultured cell line, confirming that the tumor antigen is produced by the tumor and is not due to contamination by infiltrating granulocytes.